蓝桥杯单片机知识汇总 -

标题: 蓝桥杯单片机知识汇总 [打印本页]

作者: 1475963 时间: 2019-12-29 11:40
标题: 蓝桥杯单片机知识汇总
本帖最后由 1475963 于 2019-12-29 12:37 编辑

原帖：https://www.cnblogs.com/garden6zg/p/8469705.html
1.数码管

段码显示

uchar code display[] = {0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x90, 0xbf, 0xff};

打开或关闭数码管

         P2 = (P2 & 0x1f) | 0xc0;
         P0 = order[cnt];
         P2 &= 0x1f;
         P2 = (P2 & 0x1f) | 0xe0;
         P0 = display[disbuf[cnt]];
         P2 &= 0x1f;
2.LED显示          P2 = (P2 & 0x1f) | 0x80;
         P0 = 0xfe;
         P2 &= 0x1f;
3.系统初始化

关闭外设

         P2 = ((P2 & 0x1f) | 0xa0);    //关闭全部外设
         P0 = 0x00;
         P2 &= 0x1f;
         P2 = (P2 & 0x1f) | 0xe0;       //数码管都不显示
         P0 = 0xff;
         P2 &= 0x1f;

定时器设置

         TMOD = 0x01;                //计时器0，采用方式1
         TH0 = (65536 - 2000) / 256; //定时2ms
         TL0 = (65536 - 2000) % 256;
         EA = 1;                      //打开总中断
         ET0 = 1;                      //定时器中断0打开
         TR0 = 1;                      //开始计数

串口通信设置

         SCON = 0x50; //工作方式1
         AUXR = 0x40; //模式为1T模式
         TMOD = 0x20; //定时器模式为2，自动重装
         TH1 = 256 - (11059200 / 2400 / 32); //波特率为2400
         TL1 = 256 - (11059200 / 2400 / 32);
         EA = 1;       //打开总中断
         ES = 1;       //打开串口中断
         TR1 = 1;       //打开计时器1
4.IIC
        #define SlaveAddrW 0x90
          #define SlaveAddrR 0x91
          #define EEPROMW 0xa0
         #define EEPROMR 0xa1
5.DS1302

命令字

         #define AM(X)       X
         #define PM(X)          (X + 12)
         #define DS1302_SECOND 0x80
         #define DS1302_MINUTE 0x82
         #define DS1302_HOUR    0x84
         #define DS1302_DAY    0x86
         #define DS1302_MONTH    0x88
         #define DS1302_WEEK    0x8A
         #define DS1302_YEAR    0x8C
         #define DS1302_RAM(X) (0xC0 + (X) * 2)

函数操作

         void InitDS1302(void)
         {
               Write_Ds1302(0x8E, 0x00);//关掉写保护
               Write_Ds1302(0x80, 0x50);//秒
               Write_Ds1302(0x82, 0x59);//分
               Write_Ds1302(0x84, 0x23);//时
               Write_Ds1302(0x8E, 0x80);//打开写保护
         }
         //转化时间格式
         void DS1302_GetTime(SYSTEMTIME *Time)
         {
               unsigned char ReadValue;    /* 将BCD码转换成十进制数 */
               ReadValue = Read_Ds1302(DS1302_MINUTE | 0x01);
               Time->minute = ((ReadValue & 0x70)>>4) * 10 + (ReadValue & 0x0f);
               ReadValue = Read_Ds1302(DS1302_HOUR | 0x01);
               Time->hour = ((ReadValue & 0x70)>>4) * 10 + (ReadValue & 0x0f);
         }
6.A/D
         unsigned char Rb2_Read()
         {
               unsigned char dat;
               IIC_Start();
               IIC_SendByte(0x90); //写入地址
               IIC_WaitAck();
               IIC_SendByte(0x43);  //0x43是Rb2, 0x41是光敏
               IIC_WaitAck();
               IIC_Start();
               IIC_SendByte(0x91); //读命令
               IIC_WaitAck();
               dat = IIC_RecByte();  //读取一个字节
               IIC_Ack(0);
               IIC_Stop();
               return dat;
         }
7.EEPROM（读取和写入数据都不可中断）
         unsigned char Read_EEPROM(unsigned char con)
         {
               unsigned char dat;
               IIC_Start();
               IIC_SendByte(0xa0); //写入地址
               IIC_WaitAck();

               IIC_SendByte(con);    //从起始位置开始读取
               IIC_WaitAck();

               IIC_Start();
               IIC_SendByte(0xa1); //读命令
               IIC_WaitAck();
               dat = IIC_RecByte();    //读取一个字节
               IIC_Ack(0);
               IIC_Stop();
               return dat;
         }

         void Write_EEPROM(unsigned char date, unsigned char con)
         {
               IIC_Start();
               IIC_SendByte(0xa0);
               IIC_WaitAck();
               IIC_SendByte(con);
               IIC_WaitAck();
               IIC_SendByte(date);
               IIC_WaitAck();
               IIC_Stop();
               Delay(3);       //写入后要注意延时一段时间
         }
8.DS18B20（读取温度不可中断）

延时函数

         //单总线延时函数
         void Delay_OneWire(uint t)
         {
               char  z;
               while(t--)
               for(z = 0; z < 12; z++);
         }

读取温度 /* 读取数据不可中断，可以采用关闭终端来实现 */

         unsigned int Read_Temperature()
         {
               unsigned char low,high;
               unsigned int temp;
               float t;

               init_ds18b20();       //器件初始化
               Write_DS18B20(0xcc);    //跳过读序列
               Write_DS18B20(0x44);    //启动温度转换
               Delay_OneWire(200);    //延迟一会

                init_ds18b20();
               Write_DS18B20(0xcc);    //同上
               Write_DS18B20(0xbe);    //读取温度

               low = Read_DS18B20(); //读取低位
               high = Read_DS18B20(); //读取高位
               temp = (high << 8) | low;
               t = temp * 0.0625;
               temp = t + 0.5;
               return temp;
         }
9.矩阵键盘
         sbit r1=P3^0; //4行
         sbit r2=P3^1;
         sbit r3=P3^2;
         sbit r4=P3^3;
         sbit c1=P4^4; //4列
         sbit c2=P4^2;
         sbit c3=P3^5;
         sbit c4=P3^4;

         unsigned char key_scan() //读取矩阵键盘键值
         {
               unsigned char key_value;

               r1=0;
               r2=r3=r4=1;
               c1=c2=c3=c4=1;
               else if(!c1) key_value=0;
               else if(!c2) key_value=1;
                else if(!c3) key_value=2;
               else if(!c4) key_value=3;

                r2=0;
                r1=r3=r4=1;
                c1=c2=c3=c4=1;
                if(!c1) key_value=4;
                else if(!c2) key_value=5;
                else if(!c3) key_value=6;
                else if(!c4) key_value=7;

                r3=0;
               r2=r1=r4=1;
               c1=c2=c3=c4=1;
               if(!c1) key_value=8;
               else if(!c2) key_value=9;
               else if(!c3) key_value=10;
                else if(!c4) key_value=11;

               r4=0;
                r2=r3=r1=1;
                c1=c2=c3=c4=1;
                if(!c1) key_value=12;
                else if(!c2) key_value=13;
                else if(!c3) key_value=14;
                  else if(!c4) key_value=15;
             return key_value;
         }
10.超声波测距
      #define somenops {_nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_();}
      sbit TX = P1^0; //发射引脚
      sbit RX = P1^1; //接收引脚

      //TX 引脚发送 40KHz 方波信号驱动超声波发送探头
      void send_wave(void)
      {
         unsigned char i = 8; //发送 8 个脉冲
            do
             {
         TX = 1;
      somenops;somenops;somenops;somenops;somenops;
      somenops;somenops;somenops;somenops;somenops;
        TX = 0;
        somenops;somenops;somenops;somenops;somenops;
          somenops;somenops;somenops;somenops;somenops;
          }
               while(i--);
         }
   void Check_Distance()
       {
      uint t;
             /* 关闭定时器 0 中断:计算超声波发送到返回的时间 */
              ET0 = 0;
               send_wave(); //发送方波信号
               ET0 = 1;
                TR1 = 1;       //启动计时
                while((RX == 1) && (TF1 == 0)); //等待收到脉冲
                TR1 = 0;       //关闭计时
                //发生溢出
                  if(TF1 == 1)
                  {
                     TF1 = 0;
                   distance = 99; //无返回
                  }
                  else
                  {
                   /** 计算时间 */
                     t = TH1;
                    t <<= 8;
                    t |= TL1;
                    distance = (unsigned int)(t * 12 * 0.017 / 12); //计算距离
               }
                     TH1 = 0;
                     TL1 = 0;
         }

欢迎光临 (http://www.51hei.com/bbs/)